Since airplanes were first constructed there has been a need to provide fasteners for the application of skin coverings to load carrying structures that would accommodate the shear tensile loading between a skin and its substructure. Over time the airplane industry has come to rely on mechanical fasteners to satisfy this need, particularly since evolution of airplane design and construction has resulted in airplanes manufactured almost entirely from metal.
Recent developments in aircraft design have produced a new genertion of aircraft constructed with as much as fifty percent or more advanced composite materials such as graphite/epoxy. Because of the complexity of the designs of these aircraft, today's aircraft manufacturers have come to rely on automation to economically manufacture and assemble their advanced composite parts. To date, however, a suitable means for automating the assembly of these parts has yet to be developed, causing manufacturers to continue to rely on mechanical fasteners for fastening composite structures to substructures. The use of mechanical fasteners, however, causes the cost of final assembly to be increased because of their special drilling and reinforcement requirements, and because of the need for such fasteners to be made from more expensive materials to avoid serious corrosion problems in service.